The invention concerns a device for the treatment of substrates comprising a container filled with a treatment fluid, having at least one substrate carrier that moves the substrates vertically in a reciprocating manner without a substrate support.
Devices of the aforementioned kind have been known, for instance, from DE 44 13 077 A1 and DE 195 46 990 A1 of the applicant of this present patent application and are described in the German patent applications DE 195 37 879.2, DE 196 16 402.8, DE 196 52 526.8 or DE 196 37 875.3 of the same applicant as well, which have not been published as of the filing date of this application. Devices of the aforementioned kind are being used especially advantageously for the treatment of wafers. To dry the substrates, the substrate carrier is lifted, so that the substrates on the substrate carrier are lifted out of the treatment fluid, for example, a rinsing agent, and may be dried utilizing the Marangoni method. In these devices the substrates are moved in the fluid container independent of substrate support, for example, independent of substrate and wafer cassettes, which are known, e.g., from DE 42 23 327 A1 or DE 34 29 232 A1. When rinsing or drying such substrates, these substrate supports have the disadvantage, among others, that an optimal uniform fluid flow in the fluid container is not possible because the cassette presents a flow obstacle and because the substrates in such a cassette cannot be treated with ultrasound, as suggested, for example, in the as yet unpublished documents DE 197 22 473 A1 or DE 196 16 402. The substrate support or cassette also presents a disadvantage during drying of the substrates for example, wafers, because due to their large surfaces area, edges, corners, and slots they can be dried only with difficulty and with a great time expenditure.
In the conventional devices in which the substrates are reciprocated vertically by a substrate carrier independent of a substrate support or cassette, at least at the outer surfaces of the corresponding substrates and the parallel extending container walls, a relative motion occurs, subjecting the outer surface of the substrates due to this relative motion to electrical charging effects that adversely affect this process, especially, if the substrates are highly sensitive wafers for chip manufacturing. Due to the relative motion between the externally positioned substrates of a substrate package and/or the different materials of the substrates, on the one hand, and the container walls, on the other hand, flow conditions at the side areas of the substrate package differ from the flow conditions between the substrates within the substrate package. Therefore, externally positioned substrates, or at least the side areas of externally positioned substrates facing the container wall, are treated, rinsed or dried less efficiently, so that disadvantages are observed and the productivity of the entire device is unsatisfactory.
Based on this, the object of the invention is the development of a device that can achieve a homogeneous treatment process, for instance, rinsing and drying, for all substrates regardless of their arrangement within the container.